The high-throughput screening (HTS) core laboratory will initially conduct large-scale screens of chemical libraries using assays developed by two of the four projects of this PPG application. In time it is anticipated that the HTS Core will service the screening needs of many additional biochemical and cell-based assays relevant to human cancer. The HTS Core will also assemble and manage a chemical compound library composed of drug-like molecules synthesized by chemists of the PPG application and purchased from commercial sources. The HTS Core will provide a welltrained staff to conduct both biochemical and cell-based screens using semiautomated and, later, fully automated robotic equipment. The HTS Core chemist will determine the purity and identity of compounds of interest discovered in HTS assays by the use of HPLC, mass spectroscopy and NMR spectroscopy. The HTS Core chemist will also prepare the UTSW and Tularik chemical library master and dilution plates and store and manage chemical libraries. The HTS Core computer specialist will manage databases of experimental results as well as databases that track compound identity. The HTS Core robotics technician will maintain core equipment and operate the HTS robots. All members of the HTS Core staff will train members of the PPG laboratories in the techniques required for the development and execution of HTS.